/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.gluten.extension.columnar

import org.apache.gluten.backendsapi.BackendsApiManager
import org.apache.gluten.execution.{BasicScanExecTransformer, FilterExecTransformerBase}

import org.apache.spark.sql.catalyst.expressions.PredicateHelper
import org.apache.spark.sql.catalyst.rules.Rule
import org.apache.spark.sql.execution._

/**
 * Vanilla spark just push down part of filter condition into scan, however gluten can push down all
 * filters.
 */
object PushDownFilterToScan extends Rule[SparkPlan] with PredicateHelper {
  override def apply(plan: SparkPlan): SparkPlan = plan.transformUp {
    case filter: FilterExecTransformerBase =>
      filter.child match {
        case scan: BasicScanExecTransformer
            if BackendsApiManager.getSparkPlanExecApiInstance.supportPushDownFilterToScan(
              scan) && scan.supportPushDownFilters =>
          val newScan = scan.withNewPushdownFilters(splitConjunctivePredicates(filter.cond))
          if (newScan.doValidate().ok()) {
            filter.withNewChildren(Seq(newScan))
          } else {
            filter
          }
        case _ => filter
      }
  }
}
